CC - Agendas - City Council - REGULAR - 7/10/2012

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EXHIBIT A City of Prescott 2012 Water Distribution System Model Update SCOPE OF WORK include changes in the planning of the Airport area. Carollo will meet with the City's planning and development group to obtain insights into the growth that is anticipated. A draft set of growth projections will be prepared for discussion with City staff. Unit water demands will be established based on the billing records and land use data. Growth plans and development will be prepared considering the availability and timing of the City's water resources. A workshop will be conducted where projections are presented in draft form to be reviewed and commented upon. Following the workshop the demand projections will be finalized with City input. 1.4 Operational Updates The model will be updated with changes that have occurred to the water system infrastructure and operations, including new pump curves, pump controls, PRV setpoints and other operational changes so that the model reflects the way that the system is operated today, based on information provided by the City. The model containing the updated information entered by the City based on the ISO modeling as well as the operational updates will be referred to as the 2012 model. 1.5 Model Validation Carollo will work with the City to conduct a limited field test of the water system by following the steps below: • Prepare a field test plan that identifies locations where pressure transducers could be located in the distribution system for up to a week to record pressures. The field test plan will be prepared following an evaluation of the data that can be made available that would be useful for model validation. • Work with City staff to install the pressure transducers owned by Carollo and the City for the first test. The City will then do the fieldwork for the field tests that have been developed in the field test plan. The City will then provide field test data to Carollo. • Compare the model results with the field data to determine if improvements need to be made to the model to improve the accuracy with which the model predicts actual conditions. The City and Carollo will work together to achieve a mutually acceptable accuracy range. Task 1.0 Deliverable: Prepare a draft section of the report that explains the model update and validation process, as well as the demand projections that will be applied in the model. This draft section will be prepared following the demand projections workshop and the model validation. The City will review the draft report section and comments received will be incorporated into the report final draft. h:\bd_phx\prescott\water model update\prescott water model update project 06192012.docx 3